Kids mode
This is a device-specific feature for setting up a restricted "child mode" for your phone, which, when activated, can limit the functionality of the phone to make it more child-friendly.
Depending on your device, you may be able to set a daily playtime limit, a limited contact list, limited apps and media and install apps from a Kids store - a selection of child-friendly apps.
As part of this configuration you will be asked to provide an unlock method that a child might find difficult.
For more information on this mode you should consult the web or your manufacturer's documentation.